Propeller



Aprifi 7, 1 936.

P. PEDERSEN PROPELLER Filed April 5, 1935 3 Sheets-Sheet l QTTOR/Yt) April 7, 1936;

P. PEDERSEN PROPELLER Filed April 5 1955' 5 Sheets-Sheet 2 a T Q/ QTTORNEY A ril 7, 1936. R E E EN- 2,036,491

PROPELLER Filed April 5, 1935 3 Sheets-Sheet 3 Patented Apr. 7, 1936 UNITED STATES PATENT OFFICE 8 Claims.

This invention relates to improvements in propellers and more particularly to propellers adapted for use on airplanes although it is capable of other uses. One object is to provide a propeller capable of operation with little air resistance. A further object is to provide a propeller of a reciprocating type having a working stroke and an idle stroke, automatically operative means being provided for adjusting-the propeller broadside to the wind during its working stroke and edgewise to the wind during its idle stroke.

A further object is to provide a propeller that is positive and efficient in operation and durable in use. With the foregoing and other objects in view the invention consists in the combination and arrangement of parts to be hereinafter fully described, pointed out in the claims and illustrated in the drawings which form a part of this application for patent and in which Fig. 1 is a side view of one form of the propeller, one pair of blades being shown partly broken away.

Fig. 2 is a cross sectional view taken on the line 22 of Fig. 1.

Fig. 3 is a cross sectional View taken on the line 3-3 of Fig. 1.

Fig. 4 is a longitudinal sectional view taken on the line 4-4 of Fig. 1.

, Fig. 5 is a detail view, partly in section, showing one end of the spirally grooved propeller shaft, taken on the line 55 of Fig. 6.

Fig. 6 is a fragmentary sectional view showing the spirally grooved propeller shaft and the shoe travelling therein.

Fig. 7 is a fragmentary plan view of a modified form of the propeller illustrating the blade-turning mechanism arranged at one end of the hous- Fig. 8 is a view of Fig. 7, in side elevation, taken on the line 88 thereof.

Fig. 9 is a view of Fig. 8 with the adjustable parts in an altered position.

Fig. 10 is a view of Fig. 7 with the adjustable parts in an altered position.

Fig. 11 is a fragmentary plan View similar to Fig. 7, at the beginning of a stroke.

Fig. 12 is a cross sectional view taken on the line l2-I2 of Fig. 11.

Fig. 13 is a cross sectional view of Fig. 12 with the adjustable parts in an altered position, and it is taken on the line l3l3 of Fig. 14.

Fig. 14 is a view of Fig. 11 with the adjustable .parts in an altered position.

Fig. 15 is a fragmentary sectional view taken on the line I 5--l 5 of Fig. 14.

Fig. 16 is a fragmentary sectional View taken on the line l6l6 of Fig. 10.

Fig. 17 is a fragmentary side view of the pro peller showing the application of the blade-turning mechanism. 5

Fig. 18 is an enlarged fragmentary view of a further modified form of the propeller, the blades being now in wind-cutting position.

Fig. 19 is a view of the blades, broken, in elevation.

Fig. 20 is a sectional View taken on the line 2020 of Fig. 18.

Fig. 21 is a fragmentary sectional view, enlarged, taken on the line 2 |2l of Fig. 18.

Like reference characters denote corresponding 15 parts throughout the several views.

The present propeller includes a cylindrical housing secured to the forward end of the airplane, or vehicle, and enclosing a rotary enginedriven spirally grooved propeller shaft to which 20 the propeller blades are secured for reciprocation, one type of blade being adapted to rotate at the end of each stroke. Secured to the forward end I of the airplane by bolts 2 is the cylindrical housing 3 having the outer end 4 closed and 25 tapered to offer the least wind resistance.

Referring now to Figs. 1 to 6, inclusive, of the drawings, the housing 3 is formed with four slots 5 spaced ninety degrees apart and extending longitudinally thereof, the ends of said slots being 30 spaced from the ends of the housing. Arranged within the housing are bearings 6 adapted to receive the disc-like ends I of the rotary shaft 8 that is fast to the propeller shaft l0 and that is formed with spiral grooves l I running from end to end thereof back and forth, said spiral grooves ll terminating at each end, illustrated in Fig. 5, in the return groove 1 la so that a shoe travelling from one end of a spiral groove I l to the other end will be caused to return again, thus providing a continuous back and forth movement.

Mounted in the slots 5 are the propeller blades, four in number, arranged in pairs, the members of each pair being disposed diametrically opposite each other, each blade having a shaft portion l2 that connects its head [3 to its heel portion [4 which fits snugly, dove-tail fashion, in the slot 5 and is perforated to receive and retain the hollow threaded screw I5 that receives the head of the shoe [6 that runs in the spiral grooves II, the inner end or head of the shoe being engaged by an expansion coil spring I! within the screw so that the tension upon the shoe can be manually adjusted by adjustment of the screw. The head l3 of the blade is arrow-shaped in cross section so that as it moves in one direction, the idle stroke, away from the airplane it cuts the wind offering the least wind resistance and as it moves in the opposite direction, the work stroke, toward the propeller its broad but somewhat concave face is presented to the wind. The tread or tcngue portion of each shoe that rides in the roove ii is of greater length than the point of intersection, or cross-over point, of the grooves so that a shoe will not ride out of one groove H into the opposite groove at any point of intersection. Rotation of the motor shaft I rotates the shaft 8 and causes the blades to ride back and forth in the slots 5 as the shoes it ride from end to end of the shafts in the spiral grooves l i. The work strokes of the blades are those strekes toward the airplane from the outer or beveled portion of the housing.

Referring now to Figs. 7 to 17 inclusive, a modifled form of the invention is illustrated. The housing 3 is formed with longitudinally extending slots 5 in which the head blocks l8 are slidably arranged, lateral flanges of said blocks be= ing disposed in offset portions of the slots, said head blocks being recessed to snugly receive the rounded ends it of the blades 20, the shafts 2! thereof extending snugly through perforations in said head blocks, the blades proper rising above the housing 3 being of concavo-convex formation so that during the working strokes of the blades their concave faces are presented to the wind and during their idle strokes the blades are presented edgewise to the Wind, automatic bladepositioning mechanism being provided for engagement with the blades at each end of a stroke.

Each blade includes a shaft 2! that runs from the blade proper to a heel portion E4 provided With a shoe it running in the spiral grooves H.

As the blades move from the outer free end of the housing 3 toward the airplane the blades 20 are presented broadside to the wind in a power stroke. When the blades reach the inner end cf this stroke they each encounter blade-positioning mechanism. Each rounded end [9 of each blade is formed with two spaced recesses 22, 23, ninety degrees apart, said recesses being adapted alternately for alignment with a perforation 24 in the head it to releasably carry a cross-shaped pin 25 yieldingly retained in position in either recess 22, 23 by means of a spring 26 disposed in an enlarged portion of the perforation 14.

Whilethe pin 25 connects the end IQ of the blade proper with the head It the said end l9 cannot oscillate but when said pin is removed from the end l9, but retained by the head N3, the blade proper may oscillate independently of said head. Secured to a block 27 supported inside the housing is a spring 28 having its forward or free end bent slightly and bifurcated to form the prongs 2d, the inner end of the bifurcation terminating in a slightly enlarged perforation 30, the space between the forks being smaller than the head of the pin 25, the perforation 30 being at a point in line with the pin 25, and with the perforation 24 in the head block 2! at the inner end of the work stroke of the blade.

A bolt 3! supported in guides 32 upon the housing is encircled, between said guides, by an expansion coil spring 33 and connected to one end of the same so that the bolt is normally or yieldingly retained in a predetermined position with its free end in the path of the blade so that contact therewith is had as the blade completes its work stroke. The downwardly curved and bifurcated end of the spring 28 disposed in the path of movement of the pin 25 receives the same between its prongs. The outer curvature of said spring causes it to lift the pin, by its head, out of the recess 22 in the blade end [9 just previous to contact of that blade with the bolt 3|. Contact of the blade with the said bolt will oscillate the blade into a position at right angles to its stroke position and edgewise to the wind. As soon as the blade is positioned edgewise to its path of movement the recess 23 is disposed opposite the pin 25, the inner end of which will then be forced into said recess by the spring 26.

The blade, edgewise to the wind, now moves toward the outer end of the housing 3 and when at the end of this idle stroke it encounters another spring 28 that lifts its pin 25 out of the recess 23, as previously described with relation to the recess 22, and encounters the beveled end of a pawl 34 pivotally secured to a boss 35 carried by the housing 3, said pawl being pressed toward the blade by a spring 3% that provides suficient resiliency to compensate for the sharpcontact between the blade and the pawl, this contact serving to reposition. the blade broadside to thew-ind for the return or work stroke, the pin 25 now being deposited again in the recess 22 to hold'the blade in this adjusted position. "In this-manner the blade will be positioned-broadside to the wind for each work stroke and .edgewise to the wind for each idle stroke.

Referring now to Figs. 18 to 21 inclusive thev housing 3 is formed with relatively large slots 5 to receive the relatively large head blocks 1812 that are formed each with an enlarged recess to receive the pinion heads l9a. of the twin blades Zita.

The shanks of the Wings 2.0a extend through perforations 3'! in the head block, said pinion heads being mesh, said blades 20a having their upper portions inclined at an angle to provide clearance when they make a quarter turn'at the end of each stroke to begin the return stroke. One pinion head [9 of each pair of blades 20a is formed with recesses 22, 23 to receive the inner end of the pin 25. The positioning movement of one blade 20a is identical with that described for a blade 2!! and the one blade 20a instantly imparts movement, through the meshed pinion heads to its companion blade. The area of a twin blade being greater than that of a single blade 20 the twin is capable of delivering greater power in operation.

What is claimed is:-

1. In propellers, a housing, a rotary spirally grooved shaft associated with said housing, and reciprocating blades mounted to said housing and operatively connected to said grooved shaft.

2. In propellers, a housing, a rotary spirally grcoved shaft associated with said housing, reciprocating blades mounted to said housing and operatively connected to said grooved shaft, and means for automatically positioning said blades broadside to the wind during one stroke and edgewise to the wind during the opposite stroke.

3. In propellers, a slotted housing, a rotary spirally grooved shaft mounted within said housing, reciprocating blades mounted to said housing for operation in the grooved portions thereof, and connection between said blades and the said grooved shaft.

4. In propellers, a slotted cylindrical housing, the slots thereof being disposed ninety degrees apart and extending longitudinally thereof, pairs of reciprocating blades mounted in said housing slots, the members of each pair being disposed diametrically opposite each other, a rotary spirally grooved shaft mounted in said housing, and connection between said blades and said spirally grooved shaft.

5. In propellers, a slotted cylindrical housing, reciprocating blades mounted in pairs in said slots, blade positioning means arranged at the ends of said housing slots operable at the end of each blade stroke, a rotary spirally grooved shaft within said housing, and connection between said blades and shaft.

6. In propellers, a slotted cylindrical housing, reciprocating blades mounted in pairs in said slots, blade positioning means arranged at the ends of said housing slots operable at the end of each blade stroke upon the members of each pair of blades simultaneously, a rotary spirally grooved shaft within said housing, and connection between said pairs of blades and said shaft.

7. In propellers, a slotted cylindrical housing, head blocks slidable in said slots, blades adjustably mounted in said head blocks and including recessed rounded end portions, pins adjustably carried by said head blocks for removable disposition in the recesses in said rounded end portions, resilient pin adjusting means carried by said housing at the ends of its slots automatically operative at the end of each blade stroke whereby said pins are moved from one to the other of said rounded-end recesses, blade adjustment means at the ends of said housing slots operative at the end of each blade stroke, a rotary spirally grooved shaft within said housing, and connection between said shaft and said blades.

8. In propellers, a slotted cylindrical housing, a rotary spirally grooved shaft within said housing, reciprocating blades mounted to said housing for operation in the grooved portions thereof in pairs, and connection between said blades and shaft.

PEDER. PEDERSEN. 

